Disposable diapers provide substantial advantages and convenience over diapers intended to be laundered and reused, and in recent years disposable diapers have met with increased success in the marketplace. Typical disposable diaper structures include a moisture retaining layer of relatively high liquid holding capacity sandwiched between a moisture pervious facing layer and a moisture impervious plastic backing sheet to confine moisture within the moisture retaining layer. Such diapers are shown in U.S. Pat. No. 3,612,055 to Mesek et al. and in U.S. Pat. No. Re: 26,151 to Duncan et al.
Disposable diapers that have been marketed for many years have included adhesive closure systems for convenience in securing the diaper about the torso of a baby. Such adhesive closure systems have typically included separate tape tab members secured to the diaper during manufacture thereof, with the tape tab members having an exposable pressure sensitive adhesive mass thereon which are adhered to the backing sheet of the diaper to retain it in place on the baby. Initially, release sheets were removably secured to the adhesive mass of the tape tabs, to protect the adhesive mass prior to use of the diaper. More recently, a substrate of the tape tabs themselves has been coated with a release material, or otherwise treated to have release properties, with the tape tab being folded to detachably secure the adhesive mass to the release area thereof.
While prior art tape tabs have proven to be convenient to use, and effective in forming a custom fit of the diaper about the torso of an infant, several problems are inherent therein. Not the least of these problems are the added expense that separate tape tabs contribute to the overall cost of the diaper, and difficulties in consistently securing the tape tabs to the diaper by the high speed equipment used to assemble the various diaper components.
As a result of the above problems, it has been recognized by those skilled in the art that it would be desirable to provide an adhesive closure system for disposable diapers which eliminates the need for separate tape tab elements. Typical of such prior art attempts are those shown in U.S. Pat. Nos. 3,638,651 to Torr; 3,840,013 to Mesek et al; 3,848,597 to Endres; and 3,971,380 to Tritsch. For a variety of reasons such prior art attempts have not met with success, and thus the long standing problem remains.